Catalysts and process for the conversion of olefins to ketones

ABSTRACT

An improved process is provided for forming ketones from the corresponding olefins in the vapor phase in the presence of water vapor employing a heterogeneous catalyst comprising rhenium compounds and complexes, optionally containing at least one metal compound or complex selected from the group consisting of Group VIB metals and Group VIII noble metals, and mixtures thereof. It has been surprisingly found that these catalysts effect the formation of ketones in high selectivities with minimal selectivities to the undesirable carbon dioxide and carbon monoxide by-products.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a division of application Ser. No. 516,902, filedJuly 25, 1983, now U.S. Pat. No. 4,560,805, which is acontinuation-in-part of our Ser. No. 420,527, filed Sept. 21, 1982, nowabandoned, and is related to our applications filed on even dateherewith, Ser. No. 516,903, now U.S. Pat. No. 4,528,401, entitled"Improved Catalytic Process for the Manufacture of Ketone", which is acontinuation-in-part of our Ser. Nos. 420,715 and 420,627, both filed onSept. 21, 1982; Ser. No. 516,537, filed July 25, 1983, now U.S. Pat. No.4,560,804 entitled "Catalytic Process for the Manufacture of Ketones",which is a continuation-in-part of our Ser. Nos. 420,525, 420,526,420,648 and 420,71,6, all filed on Sept. 21, 1982; and Ser. No. 516,901,filed July 25, 1983, now U.S. Pat. No. 4,560,803, entitled "ImprovedCatalysts and Process for Oxidative Conversion of Olefins to Ketones",which is a continuation-in-part of our Ser. No. 420,626, filed Sept. 21,1982.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention generally relates to the catalytic vapor phase conversionof olefins to ketones, and to improved catalysts useful therein.

2. Description of the Prior Art

British Pat. No. 1,029,175 to Shell describes a vapor phase olefinoxidation process in which olefins are reacted with O₂ at temperaturesof less than 350° C. in the presence of water vapor and a halogen, usinga supported Group VIII noble metal catalyst containing either an Fe, Ni,Co or Group I or VII transition metal compound, optionally together withan alkali metal compound or one or more transition metal compounds ofGroups III-VI. While propylene oxidation is said to give acetone as themain reaction product, such halide-containing systems have severedisadvantages such as the high corrosivity of these systems.

An early patent (U.S. Pat. No. 2,523,686 to W. F. Engel of Shell)employs catalysts containing (1) an oxide of a metal of Groups II, III,IV or VI of the Periodic Table and (2) a metal or partially reducedoxide of a metal of Group IB, Group VII or Group VIII of the PeriodicTable, and prepares saturated open-ended ketones from olefins of atleast three carbon atoms per molecule in a vapor phase process in thepresence of steam and under defined conditions. The U.S. patentindicates that Mn is preferred over other Group VII metals (Re and Tc)in the patentee's catalysts. The catalysts are prepared by partialreduction of the metal oxide with H₂. Catalyst activity decreases overtime, and regeneration of these oxide catalysts are periodicallyrequired. Dutch Pat. No. 59,179, also to W. F. Engel, relates to similarcatalyst systems.

U.S. Pat. No. 3,389,965 to Shell discloses a process for producing H₂ bysteam reforming of hydrocarbon petroleum fractions over a Re-containingcatalyst at 400° to 600° C. or higher, which, of course, results in theformation of CO₂ and CO in very large amounts. The patent, however, doesnot relate to the selective, partial oxidation of olefins or alcohols orto the production of ketones and other oxygenated products.

Manganese, another Group VIIB metal, has been investigated in variouscatalyst systems as a catalyst promoter. L. Zanderighi, et al., LaChimica E L'Industria, vol. 56, n. 12, 815-820 (Dec., 1964) report, fora series of propylene-oxidations to a product mixture of acrolein,acetone, acetaldehyde, propylene oxide and methanol, using varioustungstates (WO₄ ⁻), of a series of cations, that the reactivities of thetested cations was:

Cu>>Bi>Pb>Fe>Tl>Mn. Y. Moro Oka, et al., J. Catalysis, vol.23, 183-192(1971) indicates that no oxygenated products other than carbon oxideswere found in propylene oxidation over a Mn₂ O₃ -MoO₃ catalyst.

W. H. Davenport et al., "Advances in Rhenium Catalysis", Ind. & Eng.Chem., vol. 60, no. 11, pp. 10-19 (Nov. 1968) states that the chemicaland catalytic properties of Re differ considerably from Mn. For example,whereas metallic Mn is highly reactive, slowly decomposes water andreacts with dilute acids, Re metal is relatively inert and does notreact with water or nonoxidizing acids. Re catalysts are said to behighly selective hydrogenation catalysts. In the presence of H₂,supported or unsupported Re metal preferentially catalyzes the attack byH₂ upon carbonyl functions over olefinic bonds, while Re oxides catalyzethe saturation of C═C bonds first.

Re-containing hydrogenation catalysts are also disclosed in French Pat.No. 761,632 (1934); H. S. Broadbent et al., J.A.C.S., vol. 76, pp.1519-1523 (1954),; H. S. Broadbent et al., J. Org. Chem., vol. 24, pp.1847-1854 (1959); H. S. Broadbent et al., J.A.C.S., vol. 81, pp.3587-3589 (1959); H. S. Broadbent et al., J. Org. Chem., vol. 27, pp.4400-4404 (1962).

R. H. Blom et al., Hydrocarbon Proc. & Petr. Refine, vol. 43, no. 10,pp. 132-134 (Oct. 1963) and R. H. Blom et al., Ind. & Eng. Chem., vol.54, no. 4, pp. 16-22 (April 1962) discuss the use of certain Recatalysts in the dehydrogenation of alcohols to aldehydes and ketones.

Rhenium dehydrogenation catalysts are prepared in U.S.S.R. Pat. No.52,780 (1938), as abstracted at 34 Chem. Abs. 5467-7; U.S.S.R. Pat. No.114,924 (1958), as abstracted at 53 Chem. Abs. 10596f;

Belgian Pat. No. 641,143 (1963) added Re to a supported catalystcontaining Fe-Sb oxide on silica to catalyze the oxidation of propyleneto acrolein.

British Pat. No. 1,038,262 (1966) employed Re oxides to promotesupported and unsupported Co and Ni molybdates and Cu phosphate tooxidize propylene to acrolein or acrylic acid.

British Pat. No. 1,054,864 (1967) obtained significant disproportion of1-butene (62% butene conversion) over 23% Re₂ O₇ on Al₂ O₃ fat 150° C.,atm. pressure) and a space velocity of 1600, with a 62% buteneconversion chiefly to propylene and pentene, albeit with some by-productC₂ and C₆ olefins. Olefin methanthesis reactions using O₂ and Reoxide/alumina catalysts are discussed in R. Nakamura, et al., J. Molec.Catalysis, vol. 15, pp. 147-156 (1982) (which is not admitted herein tobe prior art to our invention).

Reference is also made to the additional prior art, our co-pendingapplication Ser. No. 516,901 filed July 25, 1983, now U.S. Pat. No.4,560,803 for catalytic conversion of olefins to unsaturated ketones inthe presence of molecular oxygen.

SUMMARY OF THE INVENTION

According to the improved process of this invention, ketones are formedin high selectivities in the vapor phase partial oxidation of olefins inthe presence of water vapor and molecular oxygen over a heterogeneouscatalyst comprising rhenium complexes and compounds, which can beoptionally supported with at least one metal selected from the groupconsisting of Group VIB metals and Group VIII noble metals and compoundsand complexes thereof.

It has been surprisingly found that the catalysts of this invention canprovide ketones in very high selectivities, with minimal selectivityloss to the undesirable CO and CO₂ by-products.

It has been further found that the catalysts of this invention caneffect the above results without the formation of substantial amounts ofhydrogenation by-products, such as butane from butene feeds, and sucholefin saturation by-products have been detected in the gaseouseffluents from the process of this invention in only minimal amounts, ifat all.

The process of this invention, in which the ketone is formed in an O₂-free reaction zone, also avoids the use of explosive O₂ -olefin gasmixtures and therefore greatly minimizes the hazards and expenseassociated with the handling of such O₂ -olefin gas mixtures.

DETAILED DESCRIPTION OF THE INVENTION Catalyst

The catalysts of this invention comprise compounds and complexes of Re,preferably in a supported form. The Re can be present in a variety offorms including a compound or complex thereof, alone or in admixturewith a suitable promoter for the desired ketone formation reaction. Whenpresent as a Re compound, the metal can be chemically combined with aninorganic anion such as oxygen, sulfur and halide (Br, F, Cl or I).Preferred are non-halide Re catalysts such as those selected from thegroup consisting of Re oxide, Re sulfide and mixtures thereof.Particularly preferred Re oxide and sulfides are Re₂ O₃, ReO₂, ReO₃, Re₂O₅, Re₂ O₇, Re₂ S₇, ReS₂, ReS₃ and Re₂ S₅.

The Re catalyst can optionally contain as a promoter a member selectedfrom the group consisting of a metal or metal compound or complex of aGroup VI metal, a Group VIII noble metals or a mixture thereof. Thus,also suitable as catalyst for the vapor phase process of this inventionare Re catalysts containing, as the metal or as compounds or complexesthereof, any one of Cr, Mo, W, Ru, Rh, Pd, Os, Ir and Pt. Theseadditional elemental components of the catalyst can be present as themetals themselves (that is, in the reduced state) or as compounds orcomplexes thereof, or as mixtures of the foregoing. Any of the inorganicanions discussed above with respect to Re are also suitable as anionswith which the additional Group VIB or Group VIII noble metals can becombined. As with the Re component, the Group VIB and/or noble metalwill be preferably present in the non-halide form, e.g., an oxide orsulfide. Illustrative of suitable bimetallic catalysts of this inventionare Re-Mo, Re-W, Re-Rh, Re-Cr, Re-Pd, Re-Pt, Re-Ir, Re-Ru and Re-Osoxides and sulfides, and mixtures of the foregoing. Illustrativetrimetallic catalysts of this invention are oxides and sulfides ofRe-Cr-Ru, Re-Mo-Rh, Re-W-Rh, Re-Mo-Pd, Re-Mo-Os, Re-Mo-Pt, Re-W-Pd,Re-W-Os and mixtures of the foregoing. Especially preferred are oxidesand sulfides of Rh-Re-Mo, Pd-Re-Mo and Rh-Re-W.

The Re is preferably present in the promoted catalysts of this inventionin a Re:promoter metal weight:weight ratio of from about 0.0001:1 to10:1, and more preferably from about 0.01:1 to 1:1. Thus, Re-Mo catalystwill preferably contain from about 0.0001 to 10 parts by weight of Reper part by weight of Mo, and more preferably from about 0.01 to 1 partby weight of Re per part by weight of Mo. Similarly, in Re-Rh-Mocatalysts, the weight ratio of Re:(Rh+Mo) will preferably range fromabout 0.0001 to 10:1, and more preferably from about 0.01 to 1:1.

The catalysts which are used in the process of the present invention aresolids which can be prepared by any of the methods known in the art.Furthermore, they can be employed in any suitable form, for example, asgranules, pellets, powders and the like, and they can be either used assuch or supported (as is preferred) on or admixed with an inertmaterial, such as alumina, silica, silica-alumina, zeolites, pumice, anyof the activated earths, kieselguhr, clays and the like. The preferredsupport for the catalyst of this invention is alumina, and mostpreferably gamma-alumina.

Preferred supported bimetallic Re catalysts of this invention are thosecontaining from about 0.1 to 10 wt. % Re together with from about 1 to30 wt. % of a Group VIB metal (e.g., Mo or W), and more preferably thosecontaining from about 1 to 5 wt. % Re, together with from about 3 to 15wt. % of a Group VIB metal (e.g., Mo or W), calculated as wt. % of theindicated metals based on the total weight of the supported catalyst.Preferred supported trimetallic Re catalysts of this invention are thosecontaining (based on the total weight of the supported catalyst) fromabout 0.001 to 5 wt. % of a Group VIII noble metal (e.g., Rh, Pd, Pt orRu), from about 0.1 to 10 wt. % Re together with from about 1-30 wt. %Mo, and, more preferably, those containing from about 0.1 to 1.0 wt. %of a Group VIII noble metal (e.g., Rh, Pd, Pt or Ru), from about 1 to 5wt. % Re together with from about 3 to 15 wt. % of a Group VIB metal(e.g., Mo or W), calculated as wt. % of the indicated metals based onthe total weight of the supported catalyst. Preferred supportedtrimetallic Re catalysts of this invention are those containing (basedon the total weight of the supported catalyst) from about 0.001 to 5 wt.% Rh, from about 0.1 to 10 wt. % Re together with from about 1-30 wt. %Mo, and, more preferably, those containing from about 0.1-1.0 wt. % Rh,from about 1 to 5 wt. % Re, together with from about 3 to 15 wt. % Mo.

Most preferably, the catalyst composition ranges from 1 to 30 wt. % ofcatalyst metals in relation to the total weight of the supportedcatalyst.

The supports themselves are preferably characterized by a specificsurface area of at least about 10 square meters per gram, and morepreferably from about 25 to 200 square meters per gram, (as determinedby the BET method), and by a pore volume of at least about 0.1 cc./gm,and preferably from about 0.2 to 1.5 cc./gm (as determined by mercuryporosimetry).

The catalysts can themselves be formed from a thermally decomposablesalt so that a suitable solution of the selected rhenium salt, forexample, can then be impregnated on to the surface of a catalyst supportfollowed by calcining at a temperature of at least about 400° C. forsufficient time to activate the catalyst. Generally, a time of fromabout 1 to 5 hours will be sufficient at a temperature within the rangeof 300° to 600° C. This calcining step can be performed in air or in thepresence of H₂ S or an inert gas such as nitrogen, helium and the like.The particular decomposable compound selected will influence the anionassociated with the Re and promoter cations in the supported catalystfollowing the calcining step. Thus, a thio-salt of Re and/or promoter,such as ammonium thiorhenates or ammonium thiomolybdates, will begenerally calcined to form a Re sulfide catalyst. Non-thio salts, suchas the nitrate, carboxylates, carbonate and the like which do notcontain S, will generally yield a Re oxide catalyst on decompositionwhen the decomposable salt itself contains oxygen or when the calciningis conducted in an O₂ -containing gas (e.g., air). Similarly, calciningthe above S-free Re and promoter salts in the presence of an H₂ S, COS,or CS₂ atmosphere will also provide a catalyst containing Re sulfides.

The selected catalyst components (e.g., rhenium salt such as ammoniumperrhenate, the mono- or di-carboxylate of from 1 to 10 carbon atoms(e.g., the acetate, oxalate and the like), carbonate, nitrate and thelike, alone or in combination with a selected promoter compound (e.g.,ammonium permolybdate) are intimately mixed in the presence of a solventso as to produce a solution or for a flowable paste. Then the selectedsupport is impregnated with this liquid mixture and evaporation iscarried out under the selected temperature conditions to obtain a drysolids. Water may be used as the solvent for mixing the catalystcomponents, but oxygenated organic compounds such as alcohols, ethers,esters, dioxane and the like can also be used.

A particularly preferred catalyst of this invention is prepared by firstdepositing (e.g., by vacuum impregnation) the selected support (e.g.,gamma-alumina) with a thermally decomposable molybdenum compound (e.g.,ammonium permolybdate or thiomolybdate), followed by drying andcalcining to form solids having molybdenum salts deposited thereon.Thereafter, the selected decomposable rhenium compound (e.g., ammoniumperrhenate) is deposited thereon, e.g., by vacuum impregnation, followedby a second drying and calcining of the solids. If desired, a Group VIIInoble metal promoter compound (e.g., a rhodium salt such as rhodiumnitrate) can then be deposited on the Mo-Re catalyst, again followed bydrying and calcining. Alternatively, the preferred catalyst can beprepared by depositing the selected Group VIII noble metal promotercompound prior to, or simultaneously with, the deposition of the Recompound onto the surface of the solids on which molybdenum has beenpreviously deposited. Each drying step can be performed at temperatureswithin the range of from about 100° to 300° C. for a time sufficient toremove substantially all water (in the case of use of aqueous solutionsof the foregoing Mo, Re and/or Group VIII noble metals salts) or at atemperature above the solvent boiling point to about 300° C., forremoval of any other selected solvent used during the impregnation ordeposition of the metals, optionally together with passing of an inertgas such as nitrogen over the solids' surface to facilitate the removalof the water or solvent. The calcining temperatures and times are asdescribed above.

Formation of especially preferred supported Mo sulfide solids fromthermally decomposable thiomolybdate compounds is more completelydescribed in our co-pending applications, Ser. Nos. 420,715 and 420,627,filed Sept. 21, 1982, whose disclosures are hereby incorporated byreference.

The supported catalyst thus prepared will generally have a surface areaof at least about 5 m² /gm (and preferably at least 40 m² /gm) and canbe used in a fixed bed and can also be used in fluidized bed or otherconventional means of housing the catalyst particles for ultimatecontact with the gaseous reactants.

Olefin Conversion Process

The olefinic hydrocarbons which can be employed as reactants in theprocess of this invention are those which contain an aliphatic chain ofat least two carbon atoms in which there exists at least one aliphaticdouble bond, --HC═CH--. Suitable olefinic hydrocarbons are those whichare normally gaseous as well as those which are liquids at roomtemperatures but which can exist in the gaseous form at the elevatedtemperature and pressure conditions which are employed during thereaction. Representative olefinic reactants which can be employed,either alone or in combination, are propylene, 1-butene, 2-butene,1-pentene, 2-pentene, 1-hexene, 2-hexene, 3-hexene, 3-methyl-1-pentene,cyclobutene, 1-heptene, 2-heptene, 1-octene, 2-octene, 1-nonene,2-nonene, 1-decene, cyclohexene, cyclooctene, 1-dodecene, 1-hexadecene,allyl benzene, propenyl benzene, 3-phenyl-1-hexene, 4-o-tolyl-1-butene,and 1,6-di-phenyl-3-hexene. Thus, suitable olefins include (1) linearmono olefins of 2 to 20 carbon atoms, inclusive of terminal olefins,i.e., olefins, having a terminal H₂ C═CH-- group, and internal olefinshaving the carbon-carbon double bond, as a --HC═CH-- group in aninternal carbon-carbon bond of the olefin, and (2) cyclic mono-olefinsof 4 to 20 carbon atoms having a --HC═CH-- group in the cyclic ring.Particularly suitable for this invention are alkenes having from 2 to 10carbon atoms and cycloalkenes of 4 to 10 carbon atoms, and mostpreferred are linear alkenes having from 4 to 10 carbon atoms.Illustrative of these preferred classes of olefin feeds are thosecomprising 1-butene, 2-butene, 1-hexene, 1-pentene, propene, 1-octene,cyclohexene, cyclopentene, cyclobutene and the like, and mixturesthereof.

Paraffins (such as alkanes of 2 to 20 carbon atoms) and isoolefins(i.e., olefins having a >C═< group in which one or both carbon atoms arehydrocarbyl substituted, such as 2-methyl-2-butene) can be also presentin the gas feed to the oxidation zone in the practice of this invention,but they are essentially unreactive in forming the desired ketones.

Preferred olefinic feeds are olefin gas mixtures obtained from therefining of crude oil. Thus, butene cuts from such refineries typicallycontain n-butenes (1-butene and 2-butene) which will be converted bythis process into 2-butanone, and also typically contain butane andisobutene.

The process of this invention is effected by passing the selected olefinand water vapor over the surface of a catalyst of this invention underconditions such as to maintain a vaporous olefin in the reaction zone.The conditions of temperature and pressure under which this can beperformed can vary widely depending on such factors as the particularolefin selected for use, the space velocity of gases through the reactorand other factors. Generally, however a temperature of from about 125°to 600° C., preferably from about 200° to less than about 400° C., willbe entirely suitable. Most preferably, where the alkene comprisesbutene-1 or butene-2, the temperature within the catalyst reactor ismaintained within the range of from about 250° to 375° C. Similarly, forcycloalkenes such as cyclohexene, a temperature range of about 125° toabout 200° C. is most preferable. The pressures are in no way criticaland will generally range from about 0 to 2000 psig, preferably fromabout 5 to 150 psig, although higher or lower pressures are alsosuitable.

The space velocity of the total gases through the oxidation reactor arealso not critical and can range from 100 to 10,000 v/v/hr., andpreferably from about 200 to 6,000 v/v/hr., where "v" represents a unitof volume (e.g., "cc").

The reaction can be carried out either batchwise, continuously, orsemi-continuously. In batch operations, the gaseous reactants may beplaced, together with the catalyst, in a suitable pressure vessel andallowed to remain there under the desired reaction conditions for asuitable reaction interval, which will generally range from about 0.01to 10 hours or more, depending on the degree of reaction completenesssought. In continuous operation, the gaseous reactants are passedthrough a body of the catalyst supported within a reactor vessel, whichcan be any of the conventional equipment employed by the industry forsuch reactions.

The water vapor can be combined and premixed with, or introducedseparately from, the olefin feed, or they can be passed to the reactionvessel via separate conduits. The manner of contacting the water vaporand olefin is not critical and any of the conventional gas-gascontacting methods employed in the industry may be used.

The ratio of olefin:water vapor can also vary widely. Generally, themolar ratio of olefin:water vapor introduced to the reactor will rangefrom about 2:1 to 1:20, preferably from about 1:1 to 1:10. However,ratios outside the foregoing ranges can also be employed.

An inert gaseous diluent such as nitrogen or paraffin can also beintroduced together with the other gaseous feeds to the reactor in orderto achieve a desired high space velocity and to minimize hot spots whichcould result in an over-oxidation of the feed and/or reactants duringthe exothermic ketone formation.

Preferably, the olefin and water vapor are contacted with a non-halidecatalyst of this invention and in the substantial absence of free halide(that is a molar ratio of free halide:olefin of less than about 1×10⁻⁵:1) in order to minimize corrosion difficulties.

The reaction zone, in which the desired reaction between the olefin andwater vapor to form the selected ketone is effected, is preferablyoxygen-free, that is, contains a molar ratio of added molecular oxygento olefin of less than about 0.01:1. Molecular oxygen, therefore, is nota desired component of the gas feed to the process and its presenceserves to increase the amount of oxygenated by-products, includingcarbon dioxide and carbon monoxide, as will be illustrated in theexamples which follow.

The gas feed is preferably substantially free of H₂ S, e.g., containsless than about 0.01 vol. % H₂ S, to avoid complicating the task ofproduct recovery and purification.

The ketones which are formed will depend, of course, on the particularolefin(s) employed in the feed. Thus, use of alkene as the olefin willresult in forming the corresponding alkanone having the same number ofcarbon atoms as the alkene fed (acetone from propylene; methyl ethylketone from 1-butene, 2-butene, or mixtures thereof; cyclohexanone fromcyclohexene). The process is particularly suitable for forming alkanoneshaving from 4 to 10 carbon atoms.

The major alcohol product formed in the process of this invention willcorrespond to the carbon skeleton of the ketone product, e.g., secondarybutyl alcohol corresponding to methyl ethyl ketone.

The ketones and alcohols produced by the process of this invention canbe recovered from the reaction mixture in any desired manner, such as bydistillation or by extraction with water or other solvents followed bydistillation. Preferably, at least a portion of the unreacted gases arerecovered and recycled to the reactor in addition to fresh feed gases inorder to maximize olefin conversion. Alternatively, a series of reactorvessels can be employed and the unreacted gases from the first vesselcan then be passed as feed to the second vessel, together with make-upgaseous olefin and water vapor as required.

Gaseous H₂, which is also formed in the overall reaction, ilustrated byequation (I) below, can be readily recovered from the reactioneffluents. ##STR1##

While not wishing to be limited thereby, it is believed that the ketoneproduct formed by the process of this invention proceeds by way of analcohol intermediate corresponding to the skeleton structure of theketone product. It is believed that this is the explanation for thequantity of alcohol product which is also formed and detected in theexamples that follow. For example, butene is converted to a mixture ofketone and secondary butyl alcohol. Accordingly, our invention alsoprovides a process for contacting such an alcohol with water vapor inthe presence of a catalyst of this invention to form a correspondingketone. Process parameters include feed ratios, reaction times, spacevelocities, temperatures, pressures and the like, which are discussedabove for the use of olefin-containing feeds, are also useful in theembodiment of this invention in which the alcohol is employed as thefeed. The molar ratio of alcohol:water vapor is generally from about0.01:1 to 100:1, and preferably from about 0.01:1 to 10:1. Alcoholswhich are suitable as feeds correspond to any of the above-discussedproduct alcohols of this invention. Therefore, particularly suitable arealkanols, and especially secondary alkanols, having from 3 to 10 carbonatoms per molecule. The utility of the catalysts of this invention forconversion of alcohols to ketones can be readily seen from the followingexamples, and it will also be apparent to one skilled in the art thatrecycle of recovered alcohol by-product to an olefin-reaction zone usinga catalyst of this invention will provide improved overall utilizationof an olefin-containing feed as a result of the further reaction of thethus-recycled alcohol by-product.

The process of this invention can be further illustrated by reference tothe following examples wherein percent conversions and selectivities aremole percent.

Product selectivities in the examples were determined by gaschromatographic analysis after steady-state conditions were observed.Products formed were methyl ethyl ketone, CO, CO₂, secondary butylalcohol, butyl mercaptan and the balance unknowns. In the Examples 1-9and 14-18, the gaseous effluents from the reactor were analyzed forbutene consumed, using isobutane as a standard and employing responsefactors determined for the GC by calibration with a known gas mixture.In Examples 10-13, the gaseous reactor effluent was passed through aseries of four traps partially filled with water. The solutions in eachtrap were analyzed by gas chromatography using dioxane as internalstandard. No internal standard was employed in Example 14.

To illustrate the surprisingly improved selectivities to methyl ethylketone which are achieved in the process of this invention and thesubstantial absence of oxygen, a trimetallic rhenium-rhodium-molybdenumsulfide catalyst of this invention was prepared and then tested in oxideform in the presence of molecular oxygen to establish a base line ofactivity. Thereafter, this oxide catalyst was converted to a sulfideform and then tested in the presence of molecular oxygen for a butenefeed to determine a base line of activity. Thereafter, a series ofsubsequent runs were conducted in which molecular oxygen was notemployed as a component of the gas feed.

EXAMPLE 1--CATALYST PREPARATION (a) Vacuum Impregnation

Gamma-alumina (30 cc.; 12-20 mesh; 100 m² /gm surface area; 0.45 cc./gmpore volume; Alfa Products) was dried in air in a Linberg furnace at500° C. for 3 hours to give a dry weight of 26.4 grams. Ammoniumparamolybdate [(NH₄)₆ Mo₇ O₂₄.4H₂ O)] (4.63 grams) was dissolved indistilled water to form a 10.6 cc. aqueous solution and transferred intoa 60 cc. dropping funnel. The catalyst support was placed in a 125 cc.glass filtering flask equipped with a side arm for pulling a vacuum, andthe filtering flask was attached to a dropping funnel using a rubberstopper. After evacuation to a pressure of -15 in.Hg, the ammoniumparamolybdate solution was added dropwise to the catalyst support toachieve complete wetness. The impregnated wet catalyst was placed in astainless steel gauze boat and dried in air at 125° C. for 1 hour, 250°C. for 1 hour and 350° C. for 1 hour, and finally calcined in air byraising the furnace temperature to 500° C. (at a rate of about 10°C./min.), which was maintained for 3 hours. After cooling to roomtemperature, the solids were then impregnated with 10.3 cc. of anaqueous solution containing 1.41 grams of ammonium perrhenate, afterwhich the same four-step drying and calcining procedure was used.Finally, these solids were impregnated with a 10.3 cc. aqueous solutioncontaining 0.57 grams of Pd(NO₃)₂, again followed by the same four-stepdrying and calcining procedure. The thus-produced solids were found tocomprise mixed oxides of palladium, rhenium and molybdenum and tocontain 1.0 wt. % Pd, 3.7 wt. % Re, and 9.5 wt. % Mo, calculated as therespective elements, based on the weight of the catalyst support.

(b) Sulfiding Procedure

Ten cc. of the foregoing oxide catalyst and 20 cc. of fused ceramicinerts (12-20 mesh) were well mixed and loaded into a test reactor whichcomprised a 24-inch (0.38 inch ID) stainless steel tubular reactorequipped with gas inlets and gas outlets at opposing ends of the tubularreactor. The reactor was then heated to a temperature of 325° C. (whichwas maintained by means of electric heating tape and a Gardsmantemperature control). Temperatures in the reactor were determined bymeans of a thermocouple positioned in the center of the catalyst bed. Agas mixture of hydrogen sulfide (190 cc./min.; charged as 6 vol. % H₂ Sin N₂) and H₂ (230 cc./min.) was charged to the reactor at a gas inletpressure of 9 psig, for 3 hours, to convert the oxide catalyst to thesulfide form. The resulting solids were then contacted under the sameflow conditions with H₂ (520 cc./min.) to strip out any absorbed,unreacted.H₂ S. The catalyst was then determined to comprise a mixtureof rhenium sulfide, palladium sulfide, and molybdenum sulfide, and tocontain 1.0% Pd, 3.7% Re and 9.5% Mo, calculated as the respectiveelements, based on the total weight of the catalyst support.

EXAMPLE 2 FOR COMPARISON

To determine the performance of the catalyst prepared in Example 1(b) inthe presence of an O₂ -containing feed, a gaseous mixture of thefollowing composition, containing butene-1, oxygen, nitrogen and watervapor was passed to the reactor described in Example 1(b): 380 cc./min.of a 10:90 vol:vol mixture of oxygen:nitrogen; 60 cc./min. of a gasmixture containing 85 vol. % butene-1 and 15 vol. % iso-butane; and 224cc. per minute of water vapor. The total gas hourly space velocity ofthe gaseous mixture through this reactor was 3984 cc/cc/hr. A gaseousinlet pressure of 9.7 psig and a temperature of 310° C. was employedthroughout the reaction (1.2 hrs.). A gaseous effluent was continuouslywithdrawn from the reactor and was sampled and analyzed by means of anon-line gas chromatograph. After achieving steady conditions, methylehtyl ketone was found to have been formed in a selectivity of about58.3% at a butene conversion of 6.5%. The following by-productselectivities were observed: 11.3 % CO₂, 5.0% CO, 5.3% secondary butylalcohol and 14.0% secondary butyl mercaptan.

EXAMPLE 3

In a series of separate runs, the Re-Mo-Pd sulfide catalyst used inComparative Example 2 was contacted with a butene feed under theconditions indicated in Table I below, except that no oxygen was passedto the reactor. The data thereby obtained are set forth in Table I.

                                      TABLE I                                     __________________________________________________________________________                   Gas Feed                                                                      (cc/min.)            % Selectivities to:                       Run                                                                              Time                                                                              Temp.                                                                             Press.                                                                            Butene     GHSV                                                                              Butene                                                                              MEK        SBA C.sub.4 SH                                                                        Product                No.                                                                              (hrs)                                                                             (°C.)                                                                      psig                                                                              (1) H.sub.2 O                                                                         N.sub.2                                                                          (2) Conv. (%)                                                                           (3) CO.sub.2                                                                          CO (4) (5) (MEK                   __________________________________________________________________________                                                           + SBA)                 1   4.0                                                                              304 9.2 60  224 380                                                                              3984                                                                              1.8   93.1                                                                              0   0  6.3 0   99.4                   2   6.4                                                                              297 9.4 31  224 170                                                                              2550                                                                              2.5   95.1                                                                              0   0  4.9 0   100.0                  3  10.1                                                                              365 9.2 60  224 380                                                                              3984                                                                              2.0   97.6                                                                              0   0  2.3 0   99.9                   4  12.0                                                                              367 9.5 104 224 730                                                                              6336                                                                              2.4   97.3                                                                              0   0  1.9 0   99.2                   5  12.8                                                                              371 9.7 60  224  0 1704                                                                              2.8   95.0                                                                              0   0  4.2 0   99.2                   __________________________________________________________________________     (1) Feed = gas mixture containing 85 vol. % butene1 and 15 vol. % nbutane     (2) Total gas hourly space velocity.                                          (3) Methyl ethyl ketone.                                                      (4) Secondary butyl alcohol.                                                  (5) Butyl mercaptan.                                                     

EXAMPLE 4

Fifteen cc. of the palladium-rhenium-molybdenum oxide catalyst preparedin Example 1(a) was further vacuum impregnated using the procedure ofExample 1(a) with a 5.1 cc. aqueous solution containing 0.069 gram ofsodium nitrate, followed by the four-step drying and calcining procedureemployed in Example 1(a). The resulting solids were found toadditionally contain 0.1 wt. % Na, calculated as the element, based onthe weight of the total catalyst support, in addition to the 1.0% Pd,3.7% Re, and 9.5% Mo. This catalyst was then mixed with inerts andsulfided using the procedure set forth above in Example 1(b), and theresulting sulfided catalyst was then employed in a series of runsfollowing the procedure of Comparative Example 2 under the conditionssummarized in Table II below.

                                      TABLE II                                    __________________________________________________________________________                  Gas Feed                                                                      (cc/min.)          Butene                                                                             % Selectivities                         Run                                                                              Time                                                                             Temp.                                                                             Press.                                                                            (1)  O.sub.2 /N.sub.2                                                                        GHSV                                                                              Conv.                                                                              MEK       SBA                                                                              C.sub.4 SH                                                                        Total Product          No.                                                                              (hrs)                                                                            (°C.)                                                                      psig                                                                              1-Butene                                                                           (2) H.sub.2 O                                                                        N.sub.2                                                                          (3) (%)  (4) CO.sub.2                                                                         CO (5)                                                                              (6) (MEK                   __________________________________________________________________________                                                           + SBA)                 1  0.7                                                                              304 9.4 60   380 224                                                                               0 3984                                                                               10.8                                                                              39.8                                                                              13.5                                                                             14.6                                                                             2.8                                                                              1.4  42.6                  2  3.2                                                                              298 9.7 60    0  224                                                                              380                                                                              3984                                                                              1.6  92.2                                                                              0  0  7.8                                                                              0   100.0                  3  6.6                                                                              294 9.7 104   0  224                                                                              730                                                                              6336                                                                              2.2  95.4                                                                              0  0  4.6                                                                              0   100.0                  4  12.7                                                                             372 7.2 60    0  224                                                                               0 1704                                                                              5.2  96.8                                                                              0  0  2.4                                                                              0    99.2                  __________________________________________________________________________     (1) Feed = gas mixture containing 85 vol. % butene1, 15 vol. % nbutane.       (2) Fed as 10 vol. % O.sub.2 in N.sub.2.                                       (3) Total gas hourly space velocity.                                         (4) Methyl ethyl ketone.                                                      (5) Secondary butyl alcohol.                                                  (6) Butyl mercaptan.                                                     

EXAMPLE 5

Following the procedure of Example 1(a), 26.4 grams of dry gamma-aluminawas sequentially impregnated with Mo (using 10.6 cc. of an aqueoussolution containing 4.62 grams of ammonium paramolybdate), Re (using10.3 cc. of an aqueous solution containing 1.42 grams of ammoniumperrhenate), and finally by Rh (using 10.3 cc. of an aqueous solutioncontaining 0.37 gram of rhodium trinitrate). After each impregnation,the solids are dried under air at 125° C. for 1 hour, 250° C. for 1hour, and 350° C. for 1 hour, and then calcined under air at 500° C. for3 hours. The resulting oxide catalyst was found to comprise 0.5 wt. %Rh, 3.7 wt. % Re, and 9.7 wt. % Mo, calculated as a respective element,based on the total weight of the support. The oxide catalyst was mixedwith inerts and sulfided using the procedure of Example 1(b), and theresulting sulfided catalyst was employed in a series of runs followingthe procedure of Comparative Example 2 using conditions set forth inTable III.

                                      TABLE III                                   __________________________________________________________________________                  Gas Feed                                                                      (cc/min.)                % Selectivities                        Run                                                                              Time                                                                             Temp.                                                                             Press.                                                                            (1)  O.sub.2 /N.sub.2                                                                        GHSV                                                                              Butene                                                                              MEK       SBA                                                                              C.sub.4 SH                No.                                                                              (hrs)                                                                            (°C.)                                                                      psig                                                                              1-Butene                                                                           (2) H.sub.2 O                                                                        N.sub.2                                                                          (3) Conv. (%)                                                                           (4) CO.sub.2                                                                         CO (5)                                                                              (6)                       __________________________________________________________________________    1  0.6                                                                              315 9.0 60   380 224                                                                               0 3984                                                                              12.0  65.3                                                                              22.7                                                                             3.4                                                                              1.3                                                                              4.1                       2  2.7                                                                              301 9.5 104  730 224                                                                               0 6336                                                                              14.0  56.5                                                                              20.7                                                                             13.0                                                                             1.1                                                                              1.9                       3  4.2                                                                              310 9.2 60    0  224                                                                              380                                                                              3984                                                                              2.3   96.9                                                                              0  0  1.1                                                                              2.0                       4  6.2                                                                              306 9.4 104   0  224                                                                              730                                                                              6336                                                                              3.5   98.2                                                                              0  0  0  1.8                       5  6.8                                                                              301 9.0 31    0  224                                                                              170                                                                              2550                                                                              3.8   98.2                                                                              0  0  1.0                                                                              0.9                       6  7.8                                                                              376 9.4 31    0  224                                                                              170                                                                              2550                                                                              8.6   93.5                                                                              0  0  1.1                                                                              5.0                       7  8.3                                                                              375 9.4 60    0  224                                                                              380                                                                              3984                                                                              6.4   98.0                                                                              0  0  0  2.0                       8  8.8                                                                              375 9.4 104   0  224                                                                              730                                                                              6336                                                                              6.5   97.1                                                                              0  0  0  2.9                       9  12.8                                                                             386 9.1 60    0  224                                                                               0 1704                                                                              12.6  98.4                                                                              0  0  0.8                                                                              0.8                       __________________________________________________________________________     (1) Feed = gas mixture containing 85 vol. % butene1, 15 vol. % nbutane.       (2) Fed as 10 vol. % O.sub.2 in N.sub.2.                                      (3) Total gas hourly space velocity.                                          (4) Methyl ethyl ketone.                                                      (5) Secondary butyl alcohol.                                                  (6) Butyl mercaptan.                                                     

EXAMPLE 6

The catalyst preparation procedure of Example 5 is repeated except thatthe catalyst solids, following the last calcining step, were thenimpregnated with 10.3 cc. of an aqueous solution containing 0.11 gram ofsodium nitrate. These impregnated solids, containing 0.1 wt. % Na, 0.5wt. % Rh, 3.7 wt. % Re and 9.5 wt. % Mo (calculated as metals, based onsupport) were then dried and calcined in air using the procedure ofExample 5, and mixed with inerts and sulfided in the reactor employingthe procedure of Example 1(b). Thereafter, the sulfided catalyst wasused in a series of runs using the procedure of Comparative Example 2.The data thereby obtained are set forth in Table IV.

                                      TABLE IV                                    __________________________________________________________________________                  Gas Feed                                                                      (cc/min.)                % Selectivities                        Run                                                                              Time                                                                             Temp.                                                                             Press.                                                                            (1)  O.sub.2 /N.sub.2                                                                        GHSV                                                                              Butene                                                                              MEK       SBA                                                                              C.sub.4 SH                No.                                                                              (hrs)                                                                            (°C.)                                                                      psig                                                                              1-Butene                                                                           (2) H.sub.2 O                                                                        N.sub.2                                                                          (3) Conv. (%)                                                                           (4) CO.sub.2                                                                         CO (5)                                                                              (6)                       __________________________________________________________________________    1  0.7                                                                              285 9.1 60   380 224                                                                               0 3984                                                                              11.9  60.2                                                                              28.8                                                                             0  0.9                                                                              4.0                       2  1.8                                                                              295 9.2 104  730 224                                                                               0 6336                                                                              14.5  46.3                                                                              22.8                                                                             12.0                                                                             0.3                                                                              4.6                       3  2.4                                                                              294 9.1 60    0  224                                                                              380                                                                              3984                                                                               2.2  96.3                                                                              0  0  0  3.7                       4  7.5                                                                              300 9.0 31    0  224                                                                              170                                                                              2550                                                                               6.3  95.4                                                                              0  0  0.7                                                                              3.9                       5  9.5                                                                              357 9.0 31    0  224                                                                              170                                                                              2550                                                                              11.0  95.7                                                                              0  0  1.1                                                                              3.2                       6  11.8                                                                             375 9.1 60    0  224                                                                              380                                                                              3984                                                                               2.9  97.3                                                                              0  0  1.0                                                                              1.8                       __________________________________________________________________________     (1) Feed = gas mixture containing 85 vol. % butene1, 15 vol. % nbutane.       (2) Fed as 10 vol. % O.sub.2 in N.sub.2.                                      (3) Total gas hourly space velocity.                                          (4) Methyl ethyl ketone.                                                      (5) Secondary butyl alcohol.                                                  (6) Butyl mercaptan.                                                     

EXAMPLE 7

The catalyst preparation procedure of Example 1(a) was repeatedemploying 12.95 grams of the dry gamma-alumina support, and twoimpregnations: the first using a 5.3 cc. aqueous solution containing1.16 grams of ammonium paramolybdate; and the second using a 5.3 cc.aqueous solution containing 0.35 gram of ammonium perrhenate and 0.18gram of rhodium trinitrate, in that order. After each vacuumimpregnation the inter-stage, four-step drying/calcining procedure ofExample 1(a) was repeated, under N₂ after the first impregnation andunder air thereafter. The resulting oxide catalyst was found to contain0.5 wt. % Rh, 0.85 wt. % Re, and 4.75 wt. % Mo, calculated as therespective elements, based on the weight of the gamma-alumina support.After mixing this oxide catalyst with inerts as in Example 1(b), thecatalyst was subjected to the in situ sulfiding procedure of Example1(b) and then tested as in Example 6, providing the data summarized inTable V.

                                      TABLE V                                     __________________________________________________________________________                  Gas Feed                                                                      (cc/min.)                % Selectivities                        Run                                                                              Time                                                                             Temp.                                                                             Press.                                                                            (1)  O.sub.2 /N.sub.2                                                                        GHSV                                                                              Butene                                                                              MEK       SBA                                                                              C.sub.4 SH                No.                                                                              (hrs)                                                                            (°C.)                                                                      psig                                                                              1-Butene                                                                           (2) H.sub.2 O                                                                        N.sub.2                                                                          (3) Conv. (%)                                                                           (4) CO.sub.2                                                                         CO (5)                                                                              (6)                       __________________________________________________________________________    1  26.7                                                                             307 8.8 60   380 224                                                                               0 3984                                                                              4.5   38.9                                                                              42.9                                                                             10.7                                                                             3.3                                                                              0                         2  27.3                                                                             309 8.7 30   170 224                                                                               0 2568                                                                              4.1   50.0                                                                              43.2                                                                             0  3.8                                                                              0                         3  24.0                                                                             303 8.8 60    0  224                                                                              380                                                                              3984                                                                              1.8   92.2                                                                              0  0  7.8                                                                              0                         4  24.6                                                                             307 8.8 60    0  224                                                                              380                                                                              3984                                                                              2.0   92.4                                                                              0  0  7.6                                                                              0                         5  30.4                                                                             304 9.1 102   0  224                                                                              730                                                                              6336                                                                              1.6   96.1                                                                              0  0  3.1                                                                              0                         __________________________________________________________________________     (1) Feed = gas mixture containing 85 vol. % butene1, 15 vol. % nbutane.       (2) Fed as 10 vol. % O.sub.2 in N.sub.2.                                      (3) Total gas hourly space velocity.                                          (4) Methyl ethyl ketone.                                                      (5) Secondary butyl alcohol.                                                  (6) Butyl mercaptan.                                                     

EXAMPLE 8

Using the procedure as described above for Example 1(a), 15 cc. of thegamma-alumina (12-20 mesh) was dried in air at 500° C. for 3 hours, toprovide a dry weight of 13.4 grams. Ammonium tungstate (1.753 grams,(NH₄)₁₀ W₁₂ O₄.5H₂ O) was dissolved in water to make a 27 cc. solution,which was observed to contain some undissolved solids. In a firstimpregnation, approximately 5.3 cc. of this aqueous solution wasimpregnated onto the dried solid, after which the impregnated solidswere dried in air at 125° C. for 1 hour followed by 250° C. for 1 hour.This procedure was repeated 3 times, and a total of 0.36 gram ofinsoluble ammonium tungstate was recovered following the lastimpregnation, to provide a net of 1.39 grams of ammonium tungstateimpregnated onto the support. The above two-step drying procedure wasused after each of the successive impregnations, except that after thefifth such impregnation the catalyst was additionally dried at 350° C.for 1 hour, followed by calcining at 500° C. for 3 hours, in air. In asubsequent impregnation, 5.4 cc. of an aqueous solution containing 0.58gram of ammonium perrhenate were impregnated onto the catalyst, followedby drying at 125° C. for 1 hour, 202° C. for 1 hour, and 350° C. for 1hour, and calcining at 500° C. for 3 hours, in air. The resulting oxidecatalyst was found to contain 3.0 wt. % rhenium and 7.5 wt. % tungsten,calculated as the elements, based on the weight of the catalyst support.Ten cc. of the resulting catalyst was then mixed with 20 cc. of fusedceramic inerts (12-20 mesh) and tested as in Example 3, at theconditions summarized in Table VI, Run 1 below.

The oxide catalyst used in Run 1 was then sulfided using the procedureof Example 1(b), after which the sulfided catalyst was employed in Runs2-4, using the conditions described in Table VI.

                                      TABLE VI                                    __________________________________________________________________________                  Gas Feed                                                                      (cc/min.)                % Selectivities                        Run                                                                              Time                                                                             Temp.                                                                             Press.                                                                            (1)  O.sub.2 /N.sub.2                                                                        GHSV                                                                              Butene                                                                              MEK       SBA                          No.                                                                              (hrs)                                                                            (°C.)                                                                      psig                                                                              1-Butene                                                                           (2) H.sub.2 O                                                                        N.sub.2                                                                          (3) Conv. (%)                                                                           (4) CO.sub.2                                                                         CO (5)                          __________________________________________________________________________    Rh--W Oxide                                                                   1  2.3                                                                              313 9.4 60   380 224                                                                               0 3984                                                                              5.0   51.0                                                                              3.1                                                                              4.7                                                                              34.5                         Re--W Sulfide                                                                 2  2.5                                                                              299 9.7 60   380 224                                                                               0 3984                                                                              2.1   40.5                                                                              3.8                                                                              7.7                                                                              31.0                         3  3.5                                                                              306 9.5 60    0  224                                                                              380                                                                              3984                                                                              1.5   53.1                                                                              0  0  46.9                         4  4.0                                                                              374 9.7 60    0  224                                                                              380                                                                              3984                                                                              3.1   88.9                                                                              0  0  9.2                          __________________________________________________________________________     (1) Feed = gas mixture containing 85 vol. % butene1, 15 vol. % nbutane.       (2) Fed as 10 vol. % O.sub.2 in N.sub.2.                                      (3) Total gas hourly space velocity.                                          (4) Methyl ethyl ketone.                                                      (5) Secondary butyl alcohol.                                             

EXAMPLE 9

The catalyst preparation and sulfiding procedure of Example 5 wasrepeated (except that the reactor was loaded with 30 cc. of the oxidecatalyst prior to the in situ sulfiding step, and no solid inerts wereadmixed therewith), to prepare a sulfide catalyst, supported ongamma-alumina, comprising 0.5 wt. % Rh, 3.7 wt. % Re and 9.5 wt. % Mo,calculated as the respective element. The catalyst was then used in afirst series of runs, using N₂ in the gas feed (Runs 1-4) and then wasused in another series of runs (Runs 5-8) in which no N₂ was fed to thereactor. The data thereby obtained is set forth in Table VII below.These runs indicate the excellent stability and activity properties ofthe catalysts of this invention.

                                      TABLE VII                                   __________________________________________________________________________                  Gas Feed                                                                      (cc/min.)           % Selectivities                             Run                                                                              Time                                                                             Temp.                                                                             Press.                                                                            Butene                                                                            N.sub.2                                                                             GHSV                                                                              Butene                                                                              MEK       SBA                               No.                                                                              (hrs)                                                                            (°C.)                                                                      psig                                                                              (1) (2)                                                                              H.sub.2 O                                                                        (3) Conv. (%)                                                                           (4) CO.sub.2                                                                         CO (5)                               __________________________________________________________________________    1  11.5                                                                             357 20.6                                                                              60  380                                                                              224                                                                              3984                                                                              4.1   97.0                                                                              0  0  0.7                               2  12.1                                                                             370 8.7 60  380                                                                              224                                                                              3984                                                                              4.3   97.0                                                                              0  0  0.5                               3  12.8                                                                             359 8.9 60  380                                                                              224                                                                              3984                                                                              3.8   98.1                                                                              0  0  0.5                               4  13.3                                                                             368 9.0 60  380                                                                              224                                                                              3984                                                                              3.9   96.7                                                                              0  0  0.8                               5  19.6                                                                             367 8.0 60   0 224                                                                              1704                                                                              4.4   98.8                                                                              0  0  0.7                               6  20.4                                                                             370 8.0 60   0 224                                                                              1704                                                                              4.3   98.6                                                                              0  0  1.1                               7  20.9                                                                             366 7.9 60   0 224                                                                              1704                                                                              4.5   96.6                                                                              0  0  2.7                               8  22.1                                                                             367 8.9 60   0 224                                                                              1704                                                                              4.4   98.4                                                                              0  0  1.2                               __________________________________________________________________________     (1) Feed = gas mixture containing 85 vol. % butene1 and 15 vol. %             isobutane.                                                                    (2) Fed as N.sub.2.                                                           (3) Total gas hourly space velocity.                                          (4) Methyl ethyl ketone.                                                      (5) Secondary butyl alcohol.                                             

EXAMPLE 10

Following the procedure of Example 1(a), 35 cc. of dried gamma-alumina(Alfa Producr) was sequentially impregnated with Mo (using 12.0 cc. ofaqueous solution containing 5.2 grams of ammonium permolybdate), Re(using 11.9 cc. of an aqueous solution containing 1.64 grams of ammoniumperrhenate) and finally by Rh (using 11.9 cc. of an aqueous solutioncontaining 0.422 gram of rhodium trinitrate). After each impregnation,the solids are dried under air and then calcined, using the procedure ofExample 1(a). The resulting oxide catalyst was found to comprise 0.5 wt.% Rh, 3.7 wt. % Re, and 9.7 wt. % Mo, calculated as the respectiveelements, based on the total weight of the support. The oxide catalystwas then sulfided using the procedure of Example 1(b), except that thecatalyst was not mixed with inerts (instead, 30 cc. of the oxidecatalyst was placed in the vessel for sulfiding), and except that thesulfiding step was carried out for a period of 9.0 hours. The resultingsulfided catalyst was employed in a series of runs following theprocedure of Comparative Example 2, using conditions set forth in TableVIII.

EXAMPLE 11

The catalyst preparation procedure of Example 10 was repeated employing45 cc. of the dried gamma-alumina (Alfa Product) which was sequentiallyimpregnated with 15.1 cc. of an aqueous solution containing 6.58 gramsof ammonium permolbdate, 15.1 cc. of an aqueous solution containing 2.05gram of ammonium perrhenate and 15.1 cc. of an aqueous solutioncontaining 0.534 gram rhodium trinitrate. The drying and calciningprocedure of Example 10 was used after each impregnation. Thereafter,the dried catalyst was subjected to an additional impregnation,sequentially, with 13.2 cc. of an aqueous solution containing 1.77 gramsof ammonium perrhenate followed by 12.5 cc. of an aqueous solutioncontaining 1.46 grams of rhodium trinitrate. Again, the drying andcalcining procedure of Example 10 was formed after each impregnation.The resulting oxide catalyst was found to comprise 2.1 wt. % Rh, 7.4 wt.% Re and 9.5 wt. % Mo. Thirty cc. of this catalyst was then sulfidedusing the procedure of Example 10 and employed in a series of runsfollowing the procedure of Comparative Example 2 using the conditionsset forth in Table VIII.

                                      TABLE VIII                                  __________________________________________________________________________                  Gas Feed                                                                      (cc/min.)                                                       Run                                                                              Time                                                                             Temp.                                                                             Press.                                                                            Butene    GHSV                                                                              Butene                                                                              % Selectivities                             No.                                                                              (hrs)                                                                            (°C.)                                                                      psig                                                                              (1) H.sub.2 O                                                                        N.sub.2                                                                          (2) Conv. (%)                                                                           MEK CO.sub.2                                                                         CO SBA                                                                              Others                         __________________________________________________________________________    10A                                                                               3.0                                                                             375 9.3 60  224                                                                              380                                                                               1328                                                                             5.1   95.5                                                                              0  0  0.7                                                                              3.8                            10B                                                                               8.0                                                                             375 9.0 60  224                                                                               60                                                                              688 5.1   96.7                                                                              0  0  0.7                                                                              2.6                            10C                                                                              14.0                                                                             375 9.0 60  224                                                                               60                                                                              688 3.2   97.1                                                                              0  0  0.5                                                                              2.3                            11A                                                                               3.0                                                                             300 9.6 60  224                                                                               60                                                                              688 3.7   98.3                                                                              0  0  1.1                                                                              0.7                            11B                                                                               6.1                                                                             375 9.6 60  224                                                                               60                                                                              688 6.5   95.9                                                                              0  0  0.8                                                                              3.3                            11C                                                                               9.8                                                                             375 9.6 30  224                                                                               60                                                                              688 8.4   95.1                                                                              0  0  0.7                                                                              4.2                            11D                                                                              13.5                                                                             375 9.3 30  224                                                                               0 508 7.6   98.4                                                                              0  0  0.5                                                                              1.1                            11E                                                                              18.9                                                                             375 9.9 30  224                                                                               0 508 6.9   96.6                                                                              0  0  0.6                                                                              2.8                            __________________________________________________________________________     (1) Feed = gas mixture containing 85 vol. % butene1 and 15 vol. %             isobutane.                                                                    (2) Gas hourly space velocity (cc feed/cc catalyst/hour).                

EXAMPLE 12

Following the catalyst preparation procedure of Example 10, 35 cc. ofdried gamma-alumina (UCI-L-1278) was sequentially impregnated with 14.0cc. of an aqueous solution containing 3.93 grams of ammoniumpermolybdate, 13.5 cc. of an aqueous solution containing 1.214 grams ofammonium perrhenate, 13.5 cc. of an aqueous solution containing 1.17grams of ammonium perrhenate and finally by 13.5 cc. of an aqueoussolution containing 1.262 grams of rhodium trinitrate. The resultingoxide catalyst, after the repetitive air drying and calcining after eachimpregnation, was found to comprise 2.0 wt. % Rh, 7.4 wt. % Re and 9.5wt. % Mo. This oxide catalyst was then sulfided using the conditions ofExample 10 (30 cc. of catalyst, no inerts, 9 hours) and the trimetallicsulfide catalyst was then employed in a series of runs using theconditions set forth in Table IX and following the procedure ofComparative Example 2.

EXAMPLE 13

The catalyst preparation procedure of Example 10 was repeated employing35 cc. of dried gamma-alumina (Alfa Product) and sequentialimpregnation, followed by intermediate air drying and calcining, usingimpregnation with 12.0 cc. of an aqueous solution containing 5.25 gramsof ammonium permolybdate, 12.0 cc. of an aqueous solution containing1.61 grams of ammonium perrhenate and 12.0 cc. of an aqueous solutioncontaining 0.837 gram of ammonium trinitrate. The resulting oxidecatalyst was found to comprise 1.0 wt. % Rh, 3.7 wt. % Re, and 9.5 wt. %Mo. This oxide catalyst was then sulfided using the procedure of Example10 (30 cc. catalyst, no inerts, 9 hours), and the sulfided trimetalliccatalyst was then employed in a series of runs using the conditions setforth below in Table IX and following the procedure of ComparativeExample 2.

                                      TABLE IX                                    __________________________________________________________________________                  Gas Feed                                                                      (cc/min.)                                                       Run                                                                              Time                                                                             Temp.                                                                             Press.                                                                            Butene GHSV                                                                              Butene                                                                              % Selectivities                                No.                                                                              (hrs)                                                                            (°C.)                                                                      psig                                                                              (1) H.sub.2 O                                                                        (2) Conv. (%)                                                                           MEK CO.sub.2                                                                         CO SBA                                                                              Others                            __________________________________________________________________________    12A                                                                              21.5                                                                             375 280 122 229                                                                               702                                                                               9.4  96.0                                                                              0  0  1.6                                                                              2.4                               12B                                                                              24.5                                                                             375 280 122 482                                                                              1208                                                                              10.8  94.6                                                                              0  0  2.0                                                                              3.5                               13A                                                                               5.8                                                                             375 286  92 482                                                                              1148                                                                              13.4  92.2                                                                              0  0  1.9                                                                              6.0                               13B                                                                               9.3                                                                             375 286  92 482                                                                              1148                                                                              12.1  95.1                                                                              0  0  1.7                                                                              3.3                               13C                                                                              13.5                                                                             375  9   93 482                                                                              1150                                                                               1.7  95.9                                                                              0  0  1.4                                                                              2.7                               13D                                                                              18.5                                                                             375 800 121 482                                                                              1206                                                                              12.9  94.7                                                                              0  0  2.0                                                                              3.3                               13E                                                                              21.5                                                                             375 800 121 482                                                                              1206                                                                              10.2  95.7                                                                              0  0  2.2                                                                              2.1                               __________________________________________________________________________     (1) 99+% butene1. No N.sub.2 was used in the feed to the reactor in these     runs.                                                                         (2) Gas hourly space velocity (cc feed/cc catalyst/hour at STP).         

EXAMPLE 14

The procedure of Example 9 is repeated in two separate runs employingthe Rh-Re-Mo sulfide catalyst except that the gas feed to the reactorcomprised 60 cc./min. cis-butene-2, 380 cc./min. N₂ and 224 cc./min.water vapor, at a pressure of 8.0 psig at the selected temperatures andfor the selected period of times, providing the following deservedresults:

Run 1: 372° C., 4.1 hrs.--3.5% butene-2 conversion, 95.9% MEKselectivity, 1.1% SBA selectivity.

Run 2: 376° C., 5.2 hrs.--3.8% butene-2 conversion, 96.6% MEKselectivity, 1.4% SBA selectivity.

No CO₂ or CO by-products were detected.

EXAMPLE 15

The catalyst vacuum impregnation procedure of Example 1(a) was repeated,except that no Pd salt was employed and the following calculated aqueoussolutions of ammonium paramolybdate and ammonium perrhenate were used tosequentially impregnate 37.0 cc. of the gamma-alumina; 12.0 cc. of anaqueous solution contains 5.24 gms. of ammonium paramolybdate; 12.0 cc.of an aqueous solution containing 1.63 grams of ammonium perrhenate. Theresulting Re-Mo oxide catalyst was then sulfided using the procedure ofExample 1(b) and employed in a series of runs for MEK formation frombutene-1 as summarized in Table X below.. The catalyst comprised 3.7 wt.% Re and 9.7 wt. % Mo, calculated as the elements. No CO₂ or CO wasdetected in any run.

                                      TABLE X                                     __________________________________________________________________________                  Gas Feed                                                                      (cc/min.)                                                       Run                                                                              Time                                                                             Temp.                                                                             Press.                                                                            Butene    GHSV                                                                              Butene                                                                              % Selectivities                             No.                                                                              (hrs)                                                                            (°C.)                                                                      psig                                                                              (1) H.sub.2 O                                                                        N.sub.2                                                                          (2) Covn. (%)                                                                           MEK CO.sub.2                                                                         CO SBA                                                                              Others                         __________________________________________________________________________    1  0.6                                                                              371 8.7 60  224                                                                              380                                                                              3984                                                                              2.5   92.5                                                                              0  0  0  9.5                            2  2.1                                                                              374 9.3 60  224                                                                              380                                                                              3984                                                                              2.4   96.7                                                                              0  0  0.5                                                                              2.8                            3  2.7                                                                              365 9.3 60  224                                                                              380                                                                              3984                                                                              3.0   98.2                                                                              0  0  0.2                                                                              1.5                            4  7.8                                                                              314 8.0 60  224                                                                              380                                                                              3984                                                                              2.3   99.0                                                                              0  0  1.0                                                                              --                             5  10.0                                                                             369 8.0 60  224                                                                              380                                                                              3984                                                                              2.3   98.6                                                                              0  0  0.5                                                                              0.9                            __________________________________________________________________________     (1) 99+% butene1.                                                             (2) Gas hourly space velocity (cc feed/cc catalyst/hour).                

EXAMPLE 16

The Re-Mo sulfide catalyst of Example 15 was employed in a series ofexperiments to illustrate the adverse affect of butadiene in a butene-1feed to the process of this invention. In a first run the catalyst iscontacted with a butene-1 feed comprising essentially pure butene-1(99+% butene-1) in the absence of any butadiene and high selectivitiesto MEK and a high selectivity to MEK was observed, as summarized for runNo. 1 in Table XI below. Thereafter, butadiene was substituted forbutene-1 (butadiene feed rate=60 cc/min.) for a total time of 1.2 hoursat a temperature of about 375° C. and a pressure of about 9.0 psig.After 0.7 hours, about 10 % of the butadiene was converted to productand methyl vinyl ketone was formed in a selectivity of about 23%. Afterabout 1.2 hours, the butadiene conversion dropped to about 3% during theinterval of 0.7 to 1.2 hours, and methyl vinyl ketone selectivity wasfound to be 26%. The thus-treated catalyst was then contacted in asecond run (Run No. 2) with a fresh butene-1 feed. After one hour, onlytrace amounts of methyl ethyl ketone were found using the conditionssummarized in Table X.

To illustrate the catalyst rejuvenation procedure of this invention, thefeed to the reactor was changed to comprise 380 cc/hr. of a 10:90vol:vol oxygen/nitrogen mixture at a temperature of 375° C., which waspassed over the catalyst at 1.0 hour. Thereafter, the resulting Re-Mooxide catalyst was sulfided with a gas mixture comprising 190 cc./min.of hydrogen sulfide (6 vol. % in nitrogen), and 220 cc./min. hydrogen ata temperature of 375° C. for 1 hour, followed by purging of the sulfidedcatalyst to remove excess H2S with 500 cc./hr. of hydrogen at 375° C.for 1/2 hour. Following this rejuvenation procedure the catalyst wasagain exposed to a fresh butene-1 feed in Runs No. 3, 4 and 5, which issummarized in Table XI. In this run, the rejuvenated catalyst was foundto be again capable of forming high selectivities of the desired methylethyl ketone from the butene-1.

                                      TABLE XI                                    __________________________________________________________________________                  Gas Feed                                                                      (cc/min.)                                                       Run                                                                              Time                                                                             Temp.                                                                             Press.                                                                            Butene    GHSV                                                                              Butene                                                                              % Selectivities                             No.                                                                              (hrs)                                                                            (°C.)                                                                      psig                                                                              (1) H.sub.2 O                                                                        N.sub.2                                                                          (2) Conv. (%)                                                                           MEK CO.sub.2                                                                         CO SBA                                                                              Others                         __________________________________________________________________________    1  2.7                                                                              383 9.0 60  224                                                                              380                                                                              3984                                                                              2.3   98.9                                                                              0  0  1.1                                                                              --                             2  1.0                                                                              375 9.0 60  224                                                                              380                                                                              3984                                                                              <0.1  trace                                                                             -- -- -- --                             3  0.7                                                                              382 8.9 60  224                                                                              380                                                                              3984                                                                              3.0   93.3                                                                              0  0  0.6                                                                              6.1                            4  1.8                                                                              379 8.9 60  224                                                                              380                                                                              3984                                                                              1.8   95.9                                                                              0  0  0.6                                                                              3.5                            5  2.3                                                                              384 8.6 60  224                                                                              380                                                                              3984                                                                              1.8   96.6                                                                              0  0  0.5                                                                              2.8                            __________________________________________________________________________     (1) 99+% butene1.                                                             (2) Gas hourly space velocity (cc feed/cc catalyst/hour).                

EXAMPLE 17

To illustrate the formation of acetone from propylene, the Rh-Re-Mosulfide catalyst prepared as in Example 14 was tested at the conditionssummarized in Table XII and high selectivities to acetone were observed.

                                      TABLE XII                                   __________________________________________________________________________               Gas Feed              Selectivities                                Time                                                                             Press.                                                                            Temp.                                                                             (cc/min.)   GHSV                                                                              Propylene        IPA                               (hrs)                                                                            psig                                                                              (°C.)                                                                      Propylene                                                                           N.sub.2                                                                          H.sub.2 O                                                                        (1) Conv. (%)                                                                           Acetone                                                                            CO.sub.2                                                                         CO (2) Others                        __________________________________________________________________________     2.2                                                                             9.3 369 60    380                                                                              224                                                                              1328                                                                              7.4   99.5 0  0  Trace                                                                             0.5                            5.0                                                                             9.3 369 60    380                                                                              224                                                                              1328                                                                              7.1   99.4 0  0  Trace                                                                             0.6                            7.2                                                                             8.6 371 60    380                                                                              224                                                                              1328                                                                              9.7   91.7 0  0  7.6 0.7                            9.5                                                                             8.6 371 60    380                                                                              224                                                                              1328                                                                              11.7  99.7 0  0  Trace                                                                             0.3                           10.0                                                                             8.7 375 60    380                                                                              224                                                                              1328                                                                              8.2   98.7 0  0  1.2 0.1                           11.0                                                                             6.1 371 60     0 224                                                                               568                                                                              12.3  85.8 0  0  Trace                                                                             14.2                          12.8                                                                             6.9 372 60     0 224                                                                               568                                                                              12.7  91.0 0  0  2.5 6.5                           13.3                                                                             6.9 369 60     0 224                                                                               568                                                                              15.3  96.1 0  0  3.5 0.4                           __________________________________________________________________________     (1) Gas hourly space velocity (cc feed/cc catalyst/hour).                     (2) IPA = isopropyl alcohol.                                             

EXAMPLE 18

To illustrate the selective conversion of cyclohexene to cyclohexanone,a series of runs are performed in which a gaseous mixture containingcyclohexene, nitrogen and water vapor is contacted with a Re-Rh-Mosulfided catalyst prepared as in Example 14, and employing theconditions summarized below in Table XIII. The data thereby obtained arealso set forth in Table XIII.

                                      TABLE XIII                                  __________________________________________________________________________               Feed Rate                                                          Time                                                                             Press.                                                                            Temp.                                                                             (cc/min.)    GHSV                                                                              Cyclohexene                                                                          Selectivity (%)                            (min)                                                                            psig                                                                              (°C.)                                                                      N.sub.2                                                                          H.sub.2 O                                                                        Cyclohexene                                                                          (1) Conv. (%)                                                                            CO.sub.2                                                                         Cyclohexanone                           __________________________________________________________________________    15 18  297 167                                                                              236                                                                              41     2664                                                                              2.1    --  1.9                                    30 18  303 167                                                                              286                                                                              38     2946                                                                              1.9    -- 24.1                                    60 18  302 167                                                                              236                                                                              37     2640                                                                              1.9    -- 15.5                                    90 18  302 167                                                                              224                                                                              45     2616                                                                              2.0    -- 17.1                                    __________________________________________________________________________     (1) Gas hourly space velocity (cc/cc/hr)                                 

In each of the foregoing examples, illustrative of the process of thisinvention, butane by-product was observed to be formed from the butenefeeds in selectivities of less than about 0.5 mol. %, based on thebutene fed to the reactor. Thus, the improved process of this inventionallows the formation of the desired ketone in the substantial absence ofolefin hydrogenation by-products, that is, the hydrogenation by-productswill be generally formed in a selectivity of less than about 1 mol. %,based on the olefin fed.

Preferably, monoolefin feeds to the process of this invention aresubstantially free (e.g., contain less than 1 wt. %) of diolefins oracetylenic hydrocarbons to obtain the highest catalyst activity to formthe ketones corresponding to the monoolefin feeds.

It will be obvious that various changes and modifications may be madewithout departing from the invention and it is intended, therefore, thatall matter contained in the foregoing description shall be interpretedas illustrative only and not limitative of the invention.

What is claimed is:
 1. A process for preparing ketones in highselectivity which comprises passing a secondary aliphatic alcohol in thegaseous phase with water vapor as feeds to a reaction zone containing acatalyst selected from the group consisting of compound or complexrhenium sulfides at a pressure of from about 0 to 2000 psig andemploying an alcohol:water molar ratio of from about 0.01 to 100:1 toform the ketone corresponding to said alcohol.
 2. The process accordingto claim 1 wherein said secondary aliphatic alcohol comprises secondarybutanol.
 3. The process according to claim 1 wherein said rheniumcatalyst additionally comprises at least one promoter selected from thegroup consisting of sulfides of Group VIB and Group VIII noble metals.4. The process according to claim 1 wherein said catalyst is supportedon gamma-alumina.
 5. The process according to claim 4 wherein saidaliphatic alcohol contains from 3 to 10 carbon atoms.
 6. The processaccording to claim 4 wherein said secondary aliphatic alcohol comprisessecondary butanol and wherein said temperature is from about 250° to375° C. and said pressure is from about 5 to 150 psig.
 7. The processaccording to claim 6 wherein said rhenium sulfide catalyst additionallycomprises at least one promoter selected from the group consisting ofsulfides of Group VI B and Group VIII noble metals.